| Autor: |
Donner, D., Bottcher, C., Messerschmidt, C., Siggel, U., Fuhrhop, J.-H |
| Zdroj: |
Langmuir; July 20, 1999, Vol. 15 Issue: 15 p5029-5039, 11p |
| Abstrakt: |
2,8,12,18-Tetraethyl-3,9,13,17-tetra-m- and p-pyridylporphyrins have been synthesized via dipyrromethanes. They form strongly fluorescing planar monolayer leaflets in water. Upon titration with ferrocyanide the m-pyridylporphyrin adsorbs these anions and the fluorescence decreases drastically. One ferrocyanide ion quenches the fluorescence of about 50 porphyrin units. In the case of the p-isomer the quenching effect is much less pronounced. The zinc complex gives no defined monolayer in water, but assembles in the presence of equimolar amounts of ferrocyanide to a triple layer. Here, the central porphyrins are rotated into two different orthogonal positions: one of these porphyrin molecules provides its β-pyridyl groups as axial ligands of the central zinc ions for the outer layers, the other takes part in a closed hydrophobic region, in which the β-ethyl groups of two orthogonal porphyrin ligands interact. Transmission electron and atomic force microscopy were used to characterize this new type of molecular assembly. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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